Reducing the odor of oil components by means of adsorption with polymeric adsorbing agents

ABSTRACT

A process for reducing the odor of an oil. The oil being treated is first distilled by a carrier vapor or carrier gas distillation to form a distilled oil. The distilled oil is then contacted with a polymeric adsorbent; whereby the odor of the oil is reduced. The polymeric adsorbent is regenerated. The polymeric adsorbent can be a cross-linked polymer with an internal surface area of from 900 to 1500 m 2 /gram.

FIELD OF THE INVENTION

The present invention relates to a process for reducing odor in oilcomponents which is characterized in that, in addition to deodorizationby carrier vapor or carrier gas distillation, the oil components arepurified by adsorption onto polymeric adsorbents.

PRIOR ART

Oil components are widely used in the field of cosmetic and foodproducts. In the production of oil components, however, various unwantedsecondary products, often with unpleasant odors, are formed in additionto the target product. It is precisely in the sensitive cosmetic andfood markets that the sensory properties of starting products are soimportant.

In order to eliminate these troublesome secondary products, i.e. thetroublesome odor of the oil components, so-called deodorization isgenerally carried out, troublesome substances being separated off bycarrier vapor or carrier gas distillation. In many cases, the oilcomponents still have a characteristic odor even after this separationstep.

The problem addressed by the present invention was to provide a processin which the odor of oil components would be distinctly improved by theuse of easy-to-handle and regeneratable auxiliaries and the purifiedproducts would have a high degree of purity.

The use of conventional adsorbents, such as active carbon and bleachingearths, was not a solution because, in the purification of the oilcomponents, adsorbents such as these soil the filter presses forexample, so that impurities can be carried over.

However, the problem stated above can be solved by not only deodorizingthe oil components, but also purifying them using polymeric adsorbents.Oil components can be purified with particular effect using polymericadsorbents having an inner surface of 900 to 1500 m²/g.

DESCRIPTION OF THE INVENTION

Accordingly, the present invention relates to a process for reducingodor in oil components which is characterized in that, in addition todeodorization by carrier vapor or carrier gas distillation, the oilcomponents are purified by adsorption onto polymeric adsorbents.

In the same way as before, the oil components are freed from secondarycomponents in a first purification step comprising carrier vapordistillation or carrier gas distillation. This is followed by adsorptionwith a suitable polymeric adsorbent.

Oil Components

Oil components in the context of the invention are the followingcompounds:

-   -   Guerbet alcohols based on fatty alcohols containing 6 to 18 and        preferably 8 to 10 carbon atoms,    -   esters of linear C₆₋₂₂ fatty acids with linear or branched C₆₋₂₂        fatty alcohols or    -   esters of branched C₆₋₁₃ carboxylic acids with linear or        branched C₆₋₂₂ fatty alcohols such as, for example, myristyl        myristate, myristyl palmitate, myristyl stearate, myristyl        isostearate, myristyl oleate, myristyl behenate, myristyl        erucate, cetyl myristate, cetyl palmitate, cetyl stearate, cetyl        isostearate, cetyl oleate, cetyl behenate, cetyl erucate,        stearyl myristate, stearyl palmitate, stearyl stearate, stearyl        isostearate, stearyl oleate, stearyl behenate, stearyl erucate,        isostearyl myristate, isostearyl palmitate, isostearyl stearate,        isostearyl isostearate, isostearyl oleate, isostearyl behenate,        isostearyl oleate, oleyl myristate, oleyl palmitate, oleyl        stearate, oleyl isostearate, oleyl oleate, oleyl behenate, oleyl        erucate, behenyl myristate, behenyl palmitate, behenyl stearate,        behenyl isostearate, behenyl oleate, behenyl behenate, behenyl        erucate, erucyl myristate, erucyl palmitate, erucyl stearate,        erucyl isostearate, erucyl oleate, erucyl behenate and erucyl        erucate,    -   esters of linear C₆₋₂₂ fatty acids with branched alcohols, more        particularly 2-ethyl hexanol,    -   esters of C₁₈₋₃₈ alkylhydroxycarboxylic acids with linear or        branched C₆₋₂₂ fatty alcohols, more especially Dioctyl Malate,    -   triglycerides based on C₆₋₁₀ fatty acids,    -   liquid mono-, di- and triglyceride mixtures based on C₆₋₁₈ fatty        acids,    -   esters of C₂₋₁₂ dicarboxylic acids with linear or branched        alcohols containing 1 to 22 carbon atoms or polyols containing 2        to 10 carbon atoms and 2 to 6 hydroxyl groups,    -   vegetable oils,    -   linear and branched C₆₋₂₂ fatty alcohol carbonates, such as        Dicaprylyl Carbonate (Cetiol® CC) for example,    -   Guerbet carbonates based on C₆₋₁₈ and preferably C₈₋₁₀ fatty        alcohols,    -   linear or branched, symmetrical or nonsymmetrical dialkyl ethers        containing 6 to 22 carbon atoms per alkyl group, such as        Dicaprylyl Ether (Cetiol® OE).

However, oil components selected from the group consisting of 2-octyldodecanol, palmitic acid/stearic acid-2-ethylhexyl ester, triglycerideswith fatty acid chain lengths of 6 to 12 carbon atoms, di-n-octyl etherand glyceryl caprylate caprate cocoate are particularly suitable forpurification by polymeric adsorbents.

Process

The adsorption step may be carried out as an agitation process, a fixedbed process or a fluidized bed process. In one particular embodiment,the adsorption onto polymeric adsorbents is carried out as a fixed bedprocess or an agitation process.

A preferred process is characterized in that the adsorption ontopolymeric adsorbents is carried out at atmospheric pressure.

In a particularly preferred embodiment of the process, the adsorptiononto polymeric adsorbents is carried out at temperatures in the rangefrom 0 to 100° C., preferably at temperatures in the range from 20 to90° C. and more particularly at temperatures in the range from 40 to 80°C.

In another particularly preferred embodiment, the adsorption ontopolymeric adsorbents is carried out as a fixed bed process attemperatures in the range from 20 to 80° C. and at atmospheric pressure.Another preferred embodiment is characterized in that the adsorptiononto polymeric adsorbents is carried out as an agitation process attemperatures of 20 to 80° C. and at atmospheric pressure.

Polymeric Adsorbents

According to the invention, ion exchanger resins, for example, may beused as the polymeric adsorbents. However, the use of polymericadsorbents with an inner surface of 900 to 1,500 m²/g is particularlypreferred. A particularly suitable adsorbent is Purolite® MN 100, ofwhich the “made-to-measure” inner surface is comparable with that of anactive carbon. In contrast to active carbon, the polymeric adsorbent caneasily be removed from the purified product.

EXAMPLES Example 1 Fixed Bed Process

Purification of an octanoic acid/decanoic acid triglyceride with ahighly crosslinked polymeric adsorbent based on polystyrene in a fixedbed column. 65 g Purolite MN 100 (inner surface ca. 1,000 m²/g),water-moist as supplied by the manufacturer, were first washed threetimes with water heated to 70° C. to remove production-relatedimpurities and then dried at 60° C. in a drying cabinet.

An 80 cm tall double-walled glass column was filled with the adsorbent(ca. 110 ml). The adsorbent was held underneath by a frit and fixed atthe top of the column by glass balls. The nonanoic/decanoic acidtriglyceride mixture to be purified was introduced into a double-walledreceiver heated to 50° C. The triglyceride mixture was introduced intothe column of adsorbent from below at a rate of 5 bed volumes per hour(550 ml/h). A Sartorius diaphragm pump was used for this purpose. Thetemperature in the column was also 50° C.

Odor tests showed that, after passing through the column, theoctanoic/decanoic acid triglyceride mixture had a far weaker odor thanthe non-purified substance.

Regeneration of the Adsorbent

The charged adsorbent was desorbed with acetone at room temperature. Tothis end, 3 bed volumes (BV) of acetone were introduced downwards intothe column at a rate of 2 BV/h. The last bed volume of acetone was leftin the column for one hour. Another two bed volumes were then introducedinto the column at a rate of 2 BV/h. Thereafter only clear acetone letthe column. The acetone was first displaced with water at roomtemperature. The column was then rinsed with water at 80° C. for severalhours in order to flush out residues of acetone. The column could thenbe re-used for improving the odor of the nonanoic/decanoic acidtriglyceride mixture.

Example 2 Agitation Process

Purification of octyl dodecanol with a highly crosslinked polymericadsorbent based on polystyrene in a stirred container. Purolite MN 100(inner surface ca. 1,000 m²/g) was purified as in Example 1.

100 g octyl dodecanol were introduced into a 250 ml brown glass flaskequipped with a propeller stirrer and heated with continuous stirring to40° C. on a heating plate. 1 g Purolite MN 100 was then added. After 30minutes, the stirrer was switched off and the mixture was filtered witha Sartorial 0.45 μm single spray filter. The filtered octyl dodecanolhas a far weaker odor than the non-purified starting substance.

1-8. (canceled)
 9. A process for reducing odor of an oil whichcomprises: (a) distilling the oil by carrier vapor or carrier gasdistillation to form a distilled oil; and (b) contacting the distilledoil with a polymeric adsorbent; whereby, the odor of the oil is reduced.10. The process as claimed in claim 9, wherein the oil componentcomprises at least one member selected from the group consisting of2-octyl dodecanol, palmitic acid/stearic acid-2-ethyl hexyl ester,triglycerides with fatty acid chain lengths of 6 to 12 carbon atoms,di-n-octyl ether and glyceryl caprylate caprate cocoate.
 11. The processas claimed in claim 9, wherein, the contacting of the distilled oil withthe polymeric adsorbent is carried out by a process selected from thegroup consisting of fixed bed processes, mixing processes andcombinations thereof.
 12. The process as claimed in claim 9, wherein,the contacting with the polymeric adsorbents is carried out atatmospheric pressure.
 13. The process as claimed in claim 9, wherein,the contacting with the polymeric adsorbent is carried out at atemperature in a range from 0° C. to 100° C.
 14. The process as claimedin claim 9, wherein, the contacting with the polymeric adsorbent iscarried out as a fixed bed process at a temperature in the range from20° C. to 80° C. and at atmospheric pressure.
 15. The process as claimedin claim 9, wherein, the contacting with the polymeric adsorbent iscarried out with agitation at a temperature in a range of 20° C. to 80°C. and at atmospheric pressure.
 16. The process as claimed in claim 9,wherein, a cross-linked polymer with an internal surface area of 900 to1,500 m²/g comprises the polymeric adsorbent.
 17. The process of claim9, wherein, the contacting with the polymeric adsorbent is carried outat a temperature in a range of 20° C. to 90° C.
 18. The process of claim9 wherein the contacting with the polymeric adsorbent is carried out ata temperature in a range of 40° C. to 80° C.
 19. The process of claim 9wherein the polymeric adsorbent comprises an ion exchange resin.
 20. Theprocess of claim 10, wherein, the contacting of the distilled oil withthe polymeric adsorbent is carried out by a process selected from thegroup consisting of fixed bed processes, mixing processes andcombinations thereof.
 21. The process of claim 10, wherein, thecontacting with the polymeric adsorbent is carried out at atmosphericpressure.
 22. The process of claim 21, wherein, the contacting with thepolymeric adsorbent is carried out at a temperature in a range from 0°C. to 100° C.
 23. The process of claim 9 wherein the polymeric adsorbentis regeneratable.
 24. The process of claim 23 wherein the polymericadsorbent comprises a cross-linked polymer with an internal surface areaof 900 to 1500 m²/g.